机制砂中的石粉特性统计分析研究  

Statistical Analysis of Microfines Characteristics in Manufactured Sands

作　　者：章从旭 刘战鳌[2] 李北星[2] ZHANG Cong-xu;LIU Zhan-ao;LI Bei-xing(.China Communications Road & Bridge International Co,Ltd,Beijing 101121,China;State Key Laboratory of Silicate Materials for Architecture,Wuhan University of Technology,Wuhan 430070,China)

机构地区：[1]中交路桥建设有限公司,北京101121 [2]武汉理工大学硅酸盐建筑材料国家重点实验室,武汉430070

出　　处：《建材世界》2021年第6期1-5,共5页The World of Building Materials

摘　　要：石粉是机制砂中粒径小于75μm的颗粒,其含量与特性对机制砂混凝土性能有显著影响。针对现行相关标准对石粉特性的评价指标过于单一、认识不足的问题,进行了30个机制砂石粉样品的岩性、细度、粒度、粒形、需水性、活性和吸附性等理化性能测定和量化表征,并统计分析了不同石粉特性指标的分布规律。结果表明:不同机制砂中的石粉的理化特性存在较大差异。73.3%石粉样本的比表面积超过200 m^(2)/kg,70%石粉的45μm筛余在45%以下,90.4%石粉的亚甲蓝值不高于7 g/kg,81.8%石粉的流动度比低于95%,84.5%石粉的活性指数大于60%。不同石粉的需水性和活性的差异性显著低于吸附性和细度的差异性。Microfines are particles finer than 75μm in manufactured sand(MS),and both the quantity and quality of microfine have significant impact on manufactured sand concrete performances.Aiming at the problems that the understanding of the characteristics of microfines is insufficient and the evaluating index for microfine quality in the related standard is too simple,the physical and chemical properties of the microfines from the collected 30 kinds of MS were tested and quantitatively characterized,such as lithology,fineness,particle size and shape,water requirement,and activity as well as absorption,and the distribution laws of characteristic indexes of different microfines were statistically analyzed.The results show that the microfines in various MS prominently differed in the physical and chemical properties.The specific surface area of 73.3%microfines samples exceeds 200 m^(2)/kg,and the residue in the 45μm sieve of 70%samples is below 45%,the methylene blue value of 90.4%microfines samples is not higher than 7 g/kg,and the fluidity ratio of 81.8%samples is less than 95%,and the activity index of 84.5%samples is larger than 60%.It has been found that the difference of water requirement and activity of various microfines is significantly lower than that of adsorption and fineness.

关 键 词：石粉特性 细度 活性 吸附性 需水性 

分 类 号：TU5[建筑科学—建筑技术科学]